Environmental education contents in science textbooks of South Korea and the United States were compared and analyzed in order to find how to develop environmental education in elementary science education. McGraw-Hill science textbooks for third to sixth grade and science textbooks of Korea based on the 2009 Revised National Curriculum and the 2007 Revised National Curriculum were analyzed and compared. The categories were educational goals, kinds of contents, distributions of contents and tense. The result showed that the environmental education goals in science textbook of Korea and United States were biased to knowledge area. The educational contents of the United States was higher 2.5 times then Korea and distributed in all areas. In quantitative distributions in Korea were biased some special areas. Tense of educational contents were almost present. Attitudes and recognition of students varies gradually over a long period of time, the contents of environmental education will be useful "evenly distributed" for all areas and school year.